The Gary Neville wanker chant was sung by the whole stadium, 29,000 fans on 2 separate occasions, so the chant must have been heard loud and clear on TV?! If it wasn't Sly Sports Football definitely messed with the sound.
Neville is a wanker aside. Both sets of fans were constantly singing with just a few periods of quiet. It was a really good atmosphere from both sets of fans throughout the match, including lots of banter, "cheating bastards, you know what you are....
Either the mics around the pitch weren't picking up the singing and atmosphere, or Sly Sports Football did mess with the sound.